Description: X-ray diffraction and inelastic neutron scattering study of 2,6-dimethylpyrazine chloranilic acid complex

This title appears in the Scientific Report : 2007

X-ray diffraction and inelastic neutron scattering study of 2,6-dimethylpyrazine chloranilic acid complex

The DMP (.) CLA and DMP (.) CLA-d(2) crystals below 100 K are monoclinic, space group P2(1)/c with four molecules in the unit cells. Infinite chains of hydrogen bonded counterparts are formed with 0(...)N distances equal to 2.767(2) and 2.639(2) for non-deuterated DMP (.) CLA. Deuteration leads to t...

Personal Name(s):	Prager, M.
	Sawka-Dobrowolska, W. / Sobczyk, L. / Pawlukojc, A. / Grech, E. / Wischnewski, A. / Zamponi, M.
Contributing Institute:	JCNS; JCNS Streumethoden; IFF-4 Neutronenstreuung; IFF-5
Published in:	Chemical physics, 332 (2007) S. 1 - 9
Imprint:	Amsterdam [u.a.] Elsevier Science 2007
Physical Description:	1 - 9
DOI:	10.1016/j.chemphys.2006.10.024
Document Type:	Journal Article
Research Program:	Großgeräte für die Forschung mit Photonen, Neutronen und Ionen (PNI) Kondensierte Materie
Series Title:	Chemical Physics 332
Subject (ZB):	J dimethylpyrazine chloranilic acid X-ray diffraction inelastic neutron scattering
	Publikationsportal JuSER

Please use the identifier: http://dx.doi.org/10.1016/j.chemphys.2006.10.024 in citations.

The DMP (.) CLA and DMP (.) CLA-d(2) crystals below 100 K are monoclinic, space group P2(1)/c with four molecules in the unit cells. Infinite chains of hydrogen bonded counterparts are formed with 0(...)N distances equal to 2.767(2) and 2.639(2) for non-deuterated DMP (.) CLA. Deuteration leads to the Ubbelohlde effect particularly well manifested in the second short O-(HN)-N-... bridge (elongation by ca. 0.02 angstrom). In the IR spectra a Hadzi's trio of the broad absorption is observed characteristic of strong hydrogen bonds. In the INS spectra the vibrational density of states and methyl rotational tunnel splittings were determined. The temperature dependence of tunneling bands enabled to make mode assignments and to determine the methyl rotational potentials. Comparison of the results to the pure electron donor DMP was made and the difference found can be almost completely assigned to the steric changes of the environment. A weak isotope effect with deuteration of the (OHN)-N-... bridges of the DMP (.) CLA complex is assigned to a charge transfer of bel e = 0.006. (c) 2006 Elsevier B.V. All rights reserved.